Field
The present disclosure relates generally to communication systems, and more particularly, to device-to-device (D2D) communication.
Background
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). LTE is designed to support mobile broadband access through improved spectral efficiency, lowered costs, and improved services using OFDMA on the downlink, SC-FDMA on the uplink, and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
In device-to-device (D2D) communication, receive (RX) and transmit (TX) operations are scheduled based on RX and TX pools that may have a conflict in time domain. For example, D2D operations on one frequency may conflict with D2D operations on another frequency. As a result, each frequency may not get a fair allocation to D2D operations. In addition, a user equipment (UE) capable of performing D2D operations may adhere to wireless wide area network (WWAN) operations, which may have a time domain conflict with D2D operations. For example, D2D operations on one frequency may conflict with WWAN operations on the same frequency or another frequency. WWAN operations may have a higher priority over D2D operations. Thus, D2D operations may be starved.